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DRY SPOT STAPHYTECT PLUS

Code: DR0100

Introduction
Dryspot Staphytect Plus is a latex slide agglutination test ¹ for the differentiation of Staphylococcus aureus by detection of clumping factor, Protein A and certain polysaccharides found in methicillin resistant Staphylococcus aureus (MRSA) from those Staphylococci that do not possess these properties.

Principle of the Test
Traditionally, differentiation between coagulase-positive and coagulase-negative staphylococci has been performed with the tube coagulase test that detects extracellular staphylocoagulase or the slide coagulase test that detects the clumping factor (bound coagulase) present on the bacterial cell surface. Several other differentiation tests are also available including the passive haemagglutination test (Oxoid Staphylase DR0595) and the DNAase test.
It has been reported that approximately 97% of human strains of Staphylococcus aureus possess both bound coagulase and extracelluar staphylocoagulase.
Protein A is found on the cell surface of about 95% of human strains of Staphylococcus aureus and has the ability to bind the Fc portion of immunoglobulin G (IgG) ² .
It has been observed that certain methicillin-resistant strains of Staphylococcus aureus (MRSA) may express undetectable levels of clumping factor and Protein A ^3,4,5 . It has been shown however that these strains all possess capsular polysaccharide ⁶. The capsule can mask both Protein A and the clumping factor thereby preventing agglutination.
Dryspot Staphytect Plus uses blue latex particles coated with both porcine fibrinogen and rabbit IgG including specific polyclonal antibodies raised against capsular polysaccharides of Staphylococcus aureus ^7,8.
The reagent is dried onto the reaction card. When the reagent is mixed on the card with colonies of Staphylococcus aureus emulsified in saline rapid agglutination occurs through the reaction between (i) fibrinogen and clumping factor, (ii) Fc portion of IgG and Protein A (iii) specific IgG and capsular polysaccharide. Agglutination may also occur with other species which possess clumping factor or Protein A such as Staphylococcus hyicus and Staphylococcus intermedius. If neither clumping factor, Protein A nor specific capsular polysaccharides are present, agglutination will not occur and the result will be regarded as negative. The most frequent coagulase and Protein A negative isolates of staphylococci are Staphylococcus epidermidis.

Components of the kit
Dryspot Staphytect Plus Reagent cards.
Blue latex particles coated with both porcine, fibrinogen and rabbit IgG together with specific polyclonal antibodies raised against capsular polysaccharide of Staphylococcus aureus. (Test Reaction Area)
Blue latex particles sensitised with non-reactive globulin (Control Reaction Area)
4 pouches each containing 10 cards and a moisture absorbent sachet. There are 3 test and 3 control reaction areas on each card. 120 tests in total.
Plastic pouch clip for storage of opened pouches
Instruction Leaflet

Materials required but not provided:
Saline (0.85%)
Timer
Pipette or dropper (50 µl)
Sterile Microbiological Loops
A suitable laboratory disinfectant
Positive Control: Staphylococcus aureus strain such as ATCC® 25923.
Negative Control: Staphylococcus epidermidis strain such as ATCC® 12228.

References:
1. Essers, L. and Radebold, K. (1980). "Rapid and Reliable Identification of Staphylococcus aureus by a Latex Agglutination Test". J.Clin.Microbiol. 12: 641-643.
2. Taussig, M.J. (1984). Processes in Pathology and Microbiology 2nd Ed. 520-530. Blackwell, Oxford.
3. Ruane, P.J, Morgan, M.A., Citron, D.M. and Mulligan, M.E. (1986). "Failure of Rapid Agglutination Methods to Detect Oxacillin-Resistant Staphylococcus aureus". J.Clin.Microbiol. 24: 490-492.
4. Roberts, J.I.S. and Gaston, M.A. (1987). "Protein A and coagulase expression in epidemic and non-epidemic Staphylococcus aureus".J.Clin.Pathol. 40: 837-840.
5. Wanger, A.R., Morris, S.L., Ericsson, C., Singh, K.V. and LaRocco, M.T. (1992). "Latex Agglutination-Negative Methicillin-Resistant Staphylococcus aureus Recovered from Neonates: Epidemiologic Features and Comparison of Typing Methods". J.Clin. Microbiol. 30: 2583-2588.
6. Fournier, J.M., Boutonnier, A. and Bouvet, A. (1989). "Staphylococcus aureus Strains Which Are Not Identified by Rapid Agglutination Methods Are of Capsular Serotype 5". J.Clin.Microbiol.27: 1372-1374.
7. Fournier, J.M., Bouvet, A. Boutonnier, A., Audurier, A. , Goldstein, F., Pierre, J., Bure, A., Lebrun, and L., Hochkeppel, H.K. (1987). Predominance of Capsular Polysaccharide Type 5 among Oxacillin-Resistant Staphylococcus aureus".J.Clin.Microbiol. 25: 1932-1933.
8. Karakawa, W.W., Fournier, J.M., Vann, W.F., Arbeit, R., Schneerson, R.S., and Robbins, J.B. (1985). "Method for the Serological Typing of the Capsular Polysaccharides of Staphylococcus aureus". J.Clin.Microbiol. 22: 445-447.
9. Kloos, W.E., Jorgensen J.H.(1988). Staphylococci. pp.143-153. In Manual of Clinical Microbiology. 4th Edn.(Eds) Lennette, E.H., Balows, A.Hauser, W.J. and Shadomy, H.J. : Assoc. Amer.Microbiol.Washington.
10. Data on file at Oxoid Ltd.
11. Jean-Pierre, H., Darbas, H., Jean-Roussenq, A. & Boyer, G.(1989). "Pathogenicity in Two Cases of Staphylococcus schleiferi, a Recently Described Species". J.Clin.Microbiol.27: 2110-2111.
12. Freney, J., Brun, Y., Bes, M., Heugnier H., Grimont, F., Grimont, P.A.D., Nervie, C., & Fleurette, J. (1988). "Staphylococcus lugdunensis sp. nov. and Staphylococcus schleiferi sp. nov., Two species from Human Clinical Specimens". Int.J.Sup Bacteriol. 38: 168-172.
13. Phillips, W.E., and Kloos, W.E. (1981). "Identification of Coagulase-Positive Staphylococcus intermedius and Staphylococcus hyicus. subsp. hyicus Isolates from Veterinary Clinical Specimens". J.Clin.Microbiol.14: 671-673.
14. van Griethuysen, A., Bes, M., Etienne, J., Zbinden, R., and Kluytmans, J. (2000). "An International Multicenter Evaluation of a new Latex Agglutination Test for Identification of Staphylococcus aureus". Clin. Microbiol. and Infect. 6 sup1:163.
15. Schnitzler, N., Rainer, M., Conrads, G., Frank, D. and Haase, G. (1988). “Staphylococcus lugdunensis: Report of a case of Peritonitis and an Easy-To-Perform Screening Strategy”. J.Clin.Microbiol. 26: 1939–1949.
16. Ann-Herbert, A., Crowder, C. G., Hancock, G. A., Jarvis, W. R. and Thornsberry, C. (1998). “Characteristics of Coagulase-Negative Staphylococci That Help Differentiate These Species of the Family Micrococcaceae”. J.Clin.Microbiol. 36: 812–813.
17. Gregson, D. B., Low, D. E., Skulnick, M. and Simor, A. E. (1988). “Problems with Rapid Agglutination Methods for Identification of Staphylococcus aureus When Staphylococcus saprophyticus Is Being Tested”. J.Clin.Microbiol. 26: 1398–1399.
18. Myhre, E. B. and Kuusela, P. (1983). “Binding of Human Fibronectin to Group A, C and G Streptococci”. Infect.Immun. 40: 29–34.
19. Runehagen, A., Schonbeck, C., Hedneru, U., Hessel, B. and Kronvall, G. (1981). “Binding of Fibrinogen Degradation Products to S. aureus and to ß-Hemolytic Streptococci Group A, C and G”. Acta.path.microbiol. Scand., Sect B. 89: 49–55.